Valve lapping apparatus



Oct. 14, 1969 A. JUVAN VALVE LAPPING APPARATUS 2 Sheets-Sheet 1 Filed Feb. 23, 1968 INVENTOR. A LOlS J u VA N Oct. 14, 1969 A. JUVAN 3,472,032

VALVE LAPPING APPARATUS Filed Feb. 23, 1968 2 Sheets-Sheet 2 INVENTOR. AL0l5 JUVAN BY WWQ United States Patent 3,472,082 VALVE LAPPIN G APPARATUS Alois Juvan, 59-53 Madison St., Ridgewood, N.Y. 11227 Filed Feb. 23, 1968, Ser. No. 707,828 Int. Cl. F16h 21/40, 21/52 US. CI. 74-74 7 Claims ABSTRACT OF THE DISCLOSURE The present invention relates to an improved valve lapping apparatus for the precision machining and seating of combustion engine valves.

More specifically, the present invention relates to an apparatus which provides an improved lapped surface between a valve and a valve seat during the manufacture and reconditioning of internal combustion engines.

Conventional valve lapping devices, which are either machine or hand operated, generally grip the top surface of the valve mechanically with a suction device and rotate the valve back and forth through a small angular displacement over the valve seat. An abrasive material is generally applied in the form of a paste between the valve and the valve seat to permit the two surfaces to wear together to form a perfect seal. These conventional methods of valve lapping suffer from the disadvantage, in that it is difficult to accurately control the amount of resurfacing that takes place between the valve and the valve seat. Utilizing conventional valve lapping methods, the valve is generally rotated back and forth through approximately the same angular displacement so that the same surface of the valve is lapped continuously over the same portion of the valve seat. In most cases, this causes an uneven lap between the surfaces, since all portions of the valve do not evenly contact all portions of the valve seat. In order to properly lap the valve surface, the valve, after being rotated back and forth through a fixed angular displacement should be advanced a small angular displacement after each cycle in order that the valve surfaces overlap different portions of the valve seat. In order to overcome this difiiculty, it has been found that by advancing the valve a small displacement after each cycle of operation, all surfaces of the valve will have lapped over all surfaces of the valve seat after many cycles of operation to form a uniform seal between the lapped surfaces.

Accordingly, the present invention provides a simple and inexpensive apparatus for providing a uniform lap between the valve and the valve seat by advancing the valve a fixed angular displacement after each cycle of operation. The apparatus according to the invention utilizes a gear train having an input shaft which may be continuously driven by a drill press, a portable electric drill, or manually, and provides at its output an oscillating motion with a fixed angular advance for each cycle of operation. The apparatus according to the invention uses a pair of oppositely driven partial gears which are coupled to the input shaft and alternately engage and disengage a pinion gear disposed between the partial 3,472,082 Patented Oct. 14, 1969 ice gears. The pinion gear, which is connected to the output shaft coupled to the valve to be lapped, is first engaged by one of the partial gears to rotate clockwise through a fixed angular displacement, and then engaged by the second partial gear to move the output shaft in an opposite direction beyond the original starting point to a new lap position slightly in advance of the starting point. The partial gears are designed so that the first partial gear becomes disengaged from the pinion gear just before the second partial gear engages the pinion gear for its return portion of the cycle. It has been found that the use of the valve lapping apparatus according to the invention results in an improved seal between the valve and the valve seat of an engine and significantly improves engine performance.

It is therefore an object according to the present invention to provide a valve lapping apparatus which produces an improved seal between the valve and the valve seat.

It is another object according to the present invention to provide a valve lapping apparatus which utilizes a gear train mechanism to provide an evenly distributed seat over all portions of the valve and the valve seat during the valve lapping process.

It is still a further object according to the present invention to provide a valve lapping apparatus which is simple in design, easy to manufacture and reliable in operation.

Other objects and features of the present invention will become apparent from the following detailed description considered in connection with the accompanying drawings which disclose the embodiments of the present invention. It should be understood, however, that the drawings are designed for the purpose of illustration only and not as a definition of the limits of the invention, as to which reference should be made to the appended claims.

In the drawings, wherein similar reference characters denote similar elements throughout the several views;

FIG. 1 is a cross-sectional view of one embodiment of the valve lapping apparatus according to the invention;

FIG. 2 is a view taken along section 2-2 of FIG. 1;

FIG. 3 is a detailed view of the gear train of FIG. 2 shown rotated in another position;

FIG. 4 is a side view taken along section 44 of FIG. 1; and

FIG. 5 is a plan view partly in cross-section of another embodiment of the invention.

Referring to FIGS. 1-4, there is shown the apparatus according to the invention consisting in part of a gear train mechanism disposed within housing 10. Housing 10 is closed by a bell-shaped cover 17 secured to the open end of the housing by means of machine screws 33 and 34. The mechanical input drive of the gear train is a tapered shaft or mandril 11 terminating at its free end in a fiat key 35. Mandril 11 as shown in this embodiment is adapted to be received into the receptacle or drive shaft of a conventional drill press. Mandril 11 enters housing 10 through a cylindrical shaft 40 and is connected adjacent to its end to a first pinion gear 28. A cylindrical bushing 12 secured within housing 10 serves as a bearing surface for shaft 40. The end of shaft 40 which projects through first pinion 28 consists of a smaller diameter projection 41 which includes a ball bearing 26 retained and lubricated in a spherical cavity at the end of the shaft.

Pinion gear 28 engages spur gear 21 pivotably mounted on shaft 19 and secured against housing 10 by means of fastener 32. Also pivotably mounted on shaft 19 and directly coupled to spur gear 21 through spacing hub 43 is partial gear 22. Partial gear 22 consists of a spur gear similar to spur 21, and has more than half of its (22a) gear teeth removed along one side. Pinion 28 also engages idler gear 27 which is pivotably mounted within housing on shaft 50. Idler gear 27 is approximately twice in depth of pinion 28 and engages a second spur gear 24 which is pivotably mounted on shaft 18 secured to housing 10 by means of fastener 31. A second partial gear 23 is also pivotably mounted on shaft 18 and affixed to spur gear 24. Partial gear 23 also consists of a spur gear similar to spur 24 and approximately half of its teeth are removed (23a). The remaining teeth of partial gears 22 and 23 are arranged to alternately engage and disengage a second pinion gear 25 secured adjacent to the end of shaft 20. Shaft is connected through retaining flange 30 to output shaft 13 projecting through hellshaped cover 17. A cylindrical bushing 14 secured within cover 17 serves as a bearing for output shaft 13. An extension 42 of shaft 20 projecting through gear includes a spherical indentation at its end to receive ball bearing 26. The purpose of ball bearing 26 is to transfer the thrust exerted downward along the center line of shaft 11 through to the center line of output shaft 13. Mounted on the free end of output shaft 13 is a resilient plunger 15 having a suction cup for mechanically gripping the top portion of the flange of valve 16.

In an actual embodiment of the apparatus according to the invention, all gears were selected to have the same pitch and the spur gears and idler gears contained teeth each. Each pinion had 12 teeth, and partial gear 23 and cut down from 30 teeth to 15 teeth. Partial gear 22 was also cut down from a spur gear containing 30 teeth to contain only 13 teeth as shown in detail in FIGS. 2 and 3.

When power is applied to input shaft 11 with housing 10 held stationary so as to cause idler gear 27 to rotate counter-clockwise as shown in FIG. 2, spur gear 24 shown in engagement therewith will rotate clockwise and drive partial gear 23 in the same direction. Simultaneously, spur gear 21 due to its engagement with pinion 28 will rotate partial gear 22 in a counter-clockwise direction at the same speed of rotation as partial gear 23. As shown in detail in FIG. 2, partial gears 22 and 23 are arranged so that as partial gear 23 becomes disengaged from pinion 25, causing its counter-clockwise rotation to cease, partial gear 22 rotating clockwise, thereafter engages pinion 25, causing it to rotate clockwise as shown in FIG. 3. Because partial gear 23 contains 15 teeth and partial gear 22 contains only 13 teeth, it is obvious that partial gear 23 will advance pinion 25 through a greater angular distance counter-clockwise because of its two additional teeth, with respect to partial gear 22. The displacement of two additional teeth with respect to the 12 teeth of pinion 25 will cause the pinion and thus shaft 13 to advance beyond its original starting position by one-sixth of a cycle or sixty degrees. It is obvious that partial gears having a smaller number of teeth may also be utilized to oscillate and advance pinion 25 through smaller angular displacements. The sum total of the gear teeth of both partial gears may not exceed 28 teeth in order that pinion 25 may properly be disengaged by one partial gear before being engaged by the other.

Referring to FIG. 5 there is shown another embodiment according to the invention adapted for use with a portable electric drive 100. Portable drive 100, which is powered through line 101 and operated by closing switch 102, includes a motor 103 similar to that found in port able electric drills. The motor is coupled to a gear reduction box 104 to reduce the speed of rotation of the motor. The output of gear reduction 104 is coupled through apparatus may be used for other applications without limitation.

While only a few embodiments of the present invention have been shown and described, it will be understood that many changes and modifications may be made thereunto without departing from the spirit and scope of the invention as defined by the appended claims.

What is claimed is:

1. An apparatus for producing an oscillating motion on its output drive in response to a continuous motion applied to its inqut drive comprising;

a first pinion coupled to said input drive,

an idler gear pivotably engaged to said first pinion,

a first spur gear pivotably engaged to said first pinion,

a second spur gear pivotably engaged to said idler gear and positioned adjacent to said first spur gear,

a first partial gear secured to said first spur gear,

a second partial gear secured to said second spur gear,

and,

a second pinion gear coupled to said outward drive and disposed between said first and second partial gears for alternate engagement therewith.

2. The apparatus as recited in claim 1 wherein said input and output drives are coaxially aligned.

3. The apparatus as recited in claim 2 additionally comprising a thrust bearing intermediate the common ends of said input and output drives.

4. The apparatus as recited in claim 3 wherein said thrust bearing is a ball bearing pivotably retained in the end of said input drive and in contact with the end of said output drive.

5. The apparatus as recited in claim 4 wherein said input drive comprises a mandril shaft for connection to a stationary drive.

6. The apparatus as recited in claim 4 wherein said input drive comprises a portable hand operated electric motor, and gear reduction means wherein said first and second transmission means is coupled to the output of said reduction means.

7. The apparatus as recited in claim 2 wherein the number of teeth of said first and second partial gears differs by at least one tooth spacing so as to advance the output drive a small angular displacement beyond its original starting point for each cycle of operation.

References Cited UNITED STATES PATENTS 1,209,931 12/1916 Boulds 74--74 1,386,085 8/1921 Albertson 74-74 1,475,043 11/1923 Davignon et al. 74-435 1,804,138 5/1931 Yeider 7474 2,187,549 1/1940 Thompson 74-74 FRED C. MATTERN, 1a., Primary Examiner W. S. RATLIFF, IR., Assistant Examiner US. Cl. X.R. 74-435 

